Vanmiddag nog wat metingen gedaan. Een en ander al gepost op rcgroups.com. En heb niet zoveel zin om het te vertalen. Dus happy reading!
OK, the weather permitted to make some test flights today
The first goal is to experiment with the FW George provided for the YEP 80A. Make flights with different prop sizes to get a feeling as to what size is best suited so that still a reasonable speeds is achieved. After all, we do loose some speed by limiting the rpms. Second goal is to get a feeling of stability of the YEP 80A in combination with the customized FW: can it handle flying multiple battery packs back to back, how is the rpm behaviour etc.
My testing gear for today:
As you can see I taped a speed sensor tube to the wing.
I am using the 10 pole NTM Prop Drive 3536A 1400KV motor.
The outside temperature is 8 C and the wind speed is 2 Beaufort.
All lipos are preheated to about 40C right upto when they are placed in the plane.
For those of you who wonder what kind of plane this is: it's the Slipher E2K racer and the manufacturer of the kit was kind enough to lend it to me to make some test flight (thanks Winfried). I had one my self, but crashed it at British Nats in August and haven't gotten around building a new one...
So for a quick overview of the results:
From these results, my conclusion is that the 8x8 APC prop produces the best results with this motor and 4S lipo battery. It will give an average speed of 163 km/h and about 620W of consumed power.
The standard 8x6 prop limited to 15200 rpm tends to be a bit slow, 8x7 already gives an improvement, but 8x8 is even better.
When the 8x9 prop is used, the motor just can't handle it and the rpm drops below 15200 rpm, so I have marked it in the chart as "not applicable". It is clearly outside of the scop eof these measurements.
The 9x6 also does not add much, so I forget about that one too.
Looking at all the measurements taken with the 8x8 prop it pretty much shows stable behaviour. There is one exception: measurement number 60. This Nanotech is pretty beaten up, it seems time to get rid of it now (and believe me it is a really bad pack, I knew that up front). Even the much older Turnigy packs of 2011 are performing better then this one.
I have flown a maxmimum of 3 batteries one after another, no problem for the YEP and this FW!.
I show the graphs of measurement 67 and 62:

All measurements taken with the 8x8 prop look pretty much like this one here above.

Clearly operation below governor rpm of 15200.
So now I wait for Tjarko's results. He will do some testing with the Castle Creations Talon 90A ESC. That one is programmable via a laptop. The two of us decided that I would pursue the YEP low budget option and he would investigate the high range (easier programmable then the YEP, that is, if you don't have the special FW George provided...). I expect he will come up with very comparable results.
Once we can compare we will evaluate the rpm setting of 15200 (what it seems to be now).
When I get my second YEP I will do some tests as well with the 14 pole FW.
Groeten, Peet